In 2011, two groups described SPENCD to be a genetically homogenous disorder due to biallelic loss-of-function (LOF) mutations in ACP5, encoding TRAP, drawing attention to enhanced type I interferon (IFN) signalling as a prominent marker of the disease (9, 10). The gene discussed is ACP5; the disease is Spondyloenchondrodysplasia with immune dysregulation.